William Brouncker

Background

Ethnicity: His family came originally from Melksham in Wiltshire.

William Brouncker was born in 1620, in Castlelyons, County Cork, the elder son of William Brouncker, 1st Viscount Brouncker and Winifred, daughter of Sir William Leigh of Newnham. His father was created a Viscount in the Peerage of Ireland in 1645 for services to the Crown. After his father died, his title passed to William’s brother Henry in 1684, and since both were unmarried, became extinct when Henry died in 1687.

Education

Brouncker entered Oxford University at the age of sixteen and showed proficiency in mathematics, languages, and medicine. He received the degree of Doctor of Physick in 1647, and for the next few years devoted himself mainly to mathematics.

Career

After receiving the degree of Doctor of Physick in 1647, Brouncker held several offices of prominence: Member of Parliament for Westbury in 1660, president of Gresham College from 1664 to 1667, commissioner for the navy from 1664 to 1668, comptroller of the treasurer’s accounts from 1668 to 1679, and master of St. Catherine’s Hospital near the Tower from 1681 to 1684.

Brouncker was the king’s nominee for president of the Royal Society, and he was appointed without opposition - at a time when there were many talented scientists. He was reappointed annually, and he guarded his position zealously, possibly holding on to it for too long. He resigned in 1677, in effect at the suggestion of an election, and was succeeded by Sir Joseph Williamson. He was an enthusiastic supporter of the society’s bias toward experimentation and was very energetic in suggesting and assessing experimental work until Hooke took over that job. Sprat’s history records two experiments performed by Brouncker, one on the increase of weight in metals due to burning and the other on the recoil of guns.

His major scientific work was undoubtedly in mathematics. Much of his work was done in correspondence with John Wallis and was published in the latter’s books.

Brouncker was a close associate of Samuel Pepys, socially and professionally, and is mentioned many times in the Diary. Pepys valued his friendship highly, but sometimes doubted his professional ability. Brouncker shared with Pepys an interest in music, and his only published book is a translation (1653) of Descartes’s Musicae compendium with notes as long as the work itself, including a mathematical attempt to divide the diapason into seventeen equal semitones.

Achievements

• Brouncker's fame as a mathematician rests largely on an ability to solve problems set by others. If he had devoted himself more fully to his own studies, he would undoubtedly have been one of the best mathematicians during a period in which talent abounded.
  
  He was the first European to solve what is now known as Pell's equation. He was the first in England to take interest in generalized continued fractions and, following the work of John Wallis, he provided development in the generalized continued fraction of pi.
  
  One of his major achievements was recorded in the work titled, Arithmetica infinitorum. This book states that Brouncker was asked to give an alternative expression, which he did in terms of continued fractions, first used by Cataldi in 1613.
  
  A paper in the Philosophical Transactions gives a solution by Brouncker of the quadrature of a rectangular hyperbola. Brouncker also improved Neile’s method for rectifying the semicubical parabola and made at least three attempts to prove Huygen’s assertion that the cycloidal pendulum was isochronous.
  
  Also, he was one of the founders and the first President of the Royal Society.

Works

More photos

• book

  • The Anatomy of Vegetables Begun 1672

Membership

In 1660, William Brouncker was one of the founders and the first President of the Royal Society.

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  Royal Society , United Kingdom

  1660 - 1684

Connections

Brouncker never married, but lived for many years with the actress Abigail Williams and left most of his property to her. She was the daughter of Sir Henry Clere (died 1622), first and last of the Clere Baronets, and the estranged wife of John Williams, otherwise Cromwell, second son of Sir Oliver Cromwell, and first cousin to the renowned Oliver Cromwell.

Father:

Sir William Brouncker

1585-1649

Mother:

Winifred Brouncker (Leigh)

William’s mother was the daughter of William Leigh of Newenham, Warwickshire.

Brother:

Henry Brouncker

life partner:

Abigail Williams

Grandfather:

Sir Henry Brouncker

Henry Brouncker (c. 1550 – 3 June 1607), of Erlestoke, Wiltshire and West Ham, Essex, was an English politician whose later career was spent in Ireland.

References

• Dictionary of scientific biography
  1981
• Dictionary of National Biography
  1938